Ahmed Mohamed Tawfik MBBCH, MS, Presenter: Nothing to Disclose

Ahmed Abdel Razek, Abstract Co-Author: Nothing to Disclose

Claus Roedel, Abstract Co-Author: Nothing to Disclose

Nagy N. N. Naguib MSc, Abstract Co-Author: Nothing to Disclose

Markus Hambek, Abstract Co-Author: Nothing to Disclose

Thomas Josef Vogl MD, Abstract Co-Author: Nothing to Disclose

Nermin Soliman MD, Abstract Co-Author: Nothing to Disclose

To evaluate the effect of arterial input selection on calculation of perfusion CT parameters of head and neck cancer, and to reach a consensus about the use of internal carotid (ICA) instead of external carotid artery (ECA).

perfusion calculations were done for 50 dynamic CT neck examinations using deconvolution-based software. Peak enhancement values (PE) of the ICA and ECA were recorded. Blood flow (BF), blood volume (BV), Mean transit time (MTT) and permeability surface area product (PS) were calculated using ipsilateral ECA, ipsilateral ICA and contralateral ICA as input arteries. Values were compared using matched pair t-test and Pearson’s correlation coefficients r.

High significant correlation was observed between PE values of the ICA and ECA (r=0.97, p<0.0001). High correlation was observed between perfusion calculations obtained using ICA and ECA (BF: r=0.98, BV: r=0.92, MTT: r=0.91 and PS: r=0.89), ipsilateral and contralateral ICA (BF: r= 0.97, BV: r= 0.95, MTT: r= 0.93 and PS: r= 0.89), as well as left and right ICA (BF: r=0.97, BV: r=0.95, MTT: r=0.94 and PS: r=0.88). All correlations were statistically significant (p<0.0001). Significantly higher BF was observed when ispilateral rather than contralateral ICA was used (p=0.02). No other significant differences were observed between perfusion calculations obtained using ICA versus ECA, ipsilateral versus contralateral ICA, or left versus right ICA (p >0.05).

Arterial input selection has no significant effect on perfusion CT calculation of head and neck cancer. For standardization and simplification of post-processing we recommend the use of ICA instead of ECA as the arterial input due to its better visualization, perpendicular course and larger caliber which decrease partial volume effects.

ECA might better represent tumor perfusion but is difficult to identify in limited scan range. ICA gives similar results with less partial volume effects. Either side can be used in central tumors.

Tawfik, A, Abdel Razek, A, Roedel, C, Naguib, N, Hambek, M, Vogl, T, Soliman, N, Perfusion CT of Head and Neck Cancer: Effect of Arterial Input Selection.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9008428.html